A device, such as a gaming console, usually produces sound when the user plays a game with the console. When the user plays a game on such device in a public place, for example, sometimes it is desirable to let people around the user hear the sound. In other times, it is desirable to keep the sounds to the user so as not to disturb other people in the vicinity. Likewise, a mobile phone can be used for music playback and audio/video playback. There are times when the playback sound is to be shared with a group of people. There are times when the playback sound is to be heard mainly by the user so that others around the user are not disturbed.